An involute gear is disclosed. A circular base has a surface that includes an inner region and an outer region. A gear tooth extends outward from the outer region of the surface. A shape of the gear tooth is defined by a varying cross-sectional involute profile. Starting from a first involute profile that is in a plane parallel to the surface of the circular base and extending outward from a center of the circular base, each location on the first involute profile is rotated about a corresponding axis while traversing a path defined by a corresponding imaginary ray extending from the center of the circular base to that location in the first involute profile. The corresponding axis is tangential to an imaginary circle that encompasses the inner region of the surface and is perpendicular to the corresponding imaginary ray.

In a bevel gear pair, a first gear (G1) and a second gear (G2) are applied with tooth top modification, and a ratio of a distance (L1b) from a pitch circle (P1) to a starting position (R1) of the tooth top modification to a distance (L1a) from the pitch circle (P1) to a tooth top (T1) in the first gear (G1) is larger than a ratio of a distance (L2b) from a pitch circle (P2) to a starting position (R2) of the tooth top modification to a distance (L2a) from a pitch circle (P2) to a tooth top (T2) in the second gear (G2). Thus, the bevel gear pair that can achieve smooth meshing is provided.

A light-weight gear including: an annular tooth portion made of metal; a shaft extending along a central axis of the tooth portion and made of metal; and a coupling element configured to couple the shaft to the tooth portion and made of a resin, in which a joining part between the shaft and the coupling element and a joining part between the tooth portion and the coupling element are provided with irregularities configured to be engaged with one another in a circumferential direction, and corners of the irregularities are rounded to release a stress. Also, provided is a manufacturing method of a light-weight gear including: disposing the tooth portion and the shaft in a mold and injecting a molten resin into a cavity of the mold, thereby simultaneously performing injection molding of the coupling element and joining the coupling element to the tooth portion and the shaft.

A driving device in one aspect of the present disclosure includes an electric motor, a worm gear, a gear easing that stores the worm gear, a first fitting portion provided in the electric motor, a second fitting portion provided in the gear casing and fitting to the first fitting portion, and a restriction member that includes a pressure contact portion and a contact portion and restricts displacement of the worm gear along a rotation center axis thereof. The pressure contact portion is in pressure contact with one fitting portion out of the first fitting portion and the second fitting portion, and the contact portion is in contact with the other fitting portion.

A method for producing a toothing with multiple teeth of a gear element for a gas turbine engine including the following steps: predefining a tooth root shape that defines a shape of the toothing in the area of tooth roots of adjacent teeth, wherein the tooth root shape is described by a spline curve at least in certain sections, in particular completely; and forming the toothing with the tooth root shape. A toothing for a gear element includes multiple teeth and a tooth root shape which is formed in the area of tooth roots of adjacent teeth and which is formed according to a spline curve at least in certain sections, in particular completely.

A worm drive includes a worm wheel having two spaced-apart outer rims defining an annular channel therebetween for receiving at least a portion of a worm screw. Each of the rims include a set of side teeth in the annular channel extending that are spaced apart from and face the set of teeth of the other rim. The two sets of teeth capture the worm screw and mesh with the screw thread of the worm screw such that the worm screw is engaged by the teeth only on spaced-apart locations on opposite sides of the worm screw. There are no resultant forces in an axial direction of the worm wheel during operation of the worm drive. Also, the worm screw and the worm wheel are self-aligning in the axial direction of the worm wheel.

In a bevel gear pair, a first gear and a second gear are applied with tooth top modification, and a ratio of a distance from a pitch circle to a starting position of the tooth top modification to a distance from the pitch circle to a tooth top in the first gear is larger than a ratio of a distance from a pitch circle to a starting position of the tooth top modification to a distance from a pitch circle to a tooth top in the second gear. Thus, the bevel gear pair that can achieve smooth meshing is provided.

According to an aspect, a device may include a first member, a second member, and a wrist mechanism disposed between the first member and the second member. The wrist mechanism may include a first cylinder portion coupled to the first member, and a second cylinder portion coupled to the second member. The first cylinder portion may be rollably engaged with the second cylinder portion such that movement of the first cylinder portion with respect to the second cylinder portion is configured to cause the first member to move in at least two directions with respect to the second member. The second cylinder portion may be positioned with respect to the first cylinder portion such that a longitudinal axis of the second cylinder portion is orthogonal to a longitudinal axis of the first cylinder portion.

Mating bevel gears generally include a pinion gear having a body that rotates about an axis and a side gear having a body that rotates about an axis that intersects the axis of the pinion gear. Pinion gear teeth of the pinion gear have a side that defines a curvature with an involute section through which a pitch line extends and a parabolic shape between the pinion gear teeth. Side gear teeth of the side gear have a side that defines a curvature with an involute section through which a pitch line extends and a parabolic shape between the side gear teeth. The curvatures on the pinion and the side gear teeth cooperatively define a controlled relative radius of curvature section except where the involute sections are located. The controlled relative radius of curvature section defines a sum of values of radius of curvature at a point of contact between the curvatures of the pinion gear teeth and the side gear teeth. The sum has a constant or decreasing value.

A worm drive includes a worm wheel having two spaced-apart outer rims defining an annular channel therebetween for receiving at least a portion of a worm screw. Each of the rims include a set of side teeth in the annular channel extending that are spaced apart from and face the set of teeth of the other rim. The two sets of teeth capture the worm screw and mesh with the screw thread of the worm screw such that the worm screw is engaged by the teeth only on spaced-apart locations on opposite sides of the worm screw. There are no resultant forces in an axial direction of the worm wheel during operation of the worm drive. Also, the worm screw and the worm wheel are self-aligning in the axial direction of the worm wheel.